OT: 1,700 UK scientists back climate science

long

John you just made it to first class jerk on this one.

Tell us more about that exponential RTD thing.

John

I haven't done a quasi-complementary in a long time. I would have to=20 study up on some existing working circuits. LTSpice will be really=20 handy for that.

=20

There was quite a bit of wiring involved. Various strays and other = non-local=20 losses could very well have made the difference. And a 40 A spike is = non-trivial.

learned=20

news=20

Worse, they are substituting a weather model that demonstratedly does=20 not work, and calling it climate.

note=20

The scientific case was never opened, it always political. Decades and = even centuries is weather, not climate. Climate starts at kiloyears. For = further information look at the previous serious (5 degrees C) change in = temperature.

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Completely missing the point that I was making, that the current CO2 levels are some 35% higher than any recorded in the ice core data; we've got a rising temperature with no Milankovitch increase in insolation to explain it.

At least part of the evidence for the speed of change during the Younger Dryas was from dust accumulation and snow accumulation rates which can be subject to finer-grained analysis, as is demonstrated by reference 6 referred to in the Wikipedia article

Loehle seems to have missed the Arctic lake sediments which Mann and his colleagues have been getting into since 1997

note that the "Little Ice Age" temperature variations are local records of the excursions of the more-sensitive Artic local climate rather than a record of any excursion in the global average temperature.

low

Since when is every belief religous? I believe in Ohms Law - at least for resistors - and this most certainly isn't a religious belief. Don is looking at the evidence and making up his own mind, which is about as far from a religious experience as it is possible to get. I'm not arguing that he is wrong, merely that even if he is right, the fossil- fuel generated CO2 that has so far been taken up by the oceans is eventually going to come out of solution and make life difficult for us.

te

Try reading the history of the construction of the scientific case. The politicians didn't get interested until the late 1980s, which was around about the time that the ice core data was starting to come in to provide chapter and verse.

kiloyears. =A0For

temperature.

Climate can change in a few years. The Younger Dryas event is a case in point

The proximal cause of the Younger Dryas event seems to have been the draining of Lake Agassiz into the North Atlantic. Our energetic attempt to empty all the accessible fossil carbon deposits and convert them into CO2 in the atmosphere could be equally effective (in the opposite direction), if a little slower.

-- Bill Sloman, Nijmegen

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John Larkin disregards physics once again. More CO2 in the atmosphere means higher global temperatures. You can argue about how much higher, but forcing the effective emitting altitude higher for the infra-red wavelengths where CO2 is active is going to make the surface temperatures higher, and not lower.

-- Bill Sloman, Nijmegen

Before I want to use LTSpice, I'd like to do a sit-down mental walk through of a design -- one that places first priority considerations first and moves forward from there. I can do that with the basic degenerative common-emitter voltage amplifier, with or without bootstrapping. And the nice thing is that then LTSpice pretty much nails my paper calcs, in those cases. Which lets me 'discover' more subtle factors where the observed performance wasn't part of my earlier theorizing. But at least the basics were right. I don't like to work out the basics by 'hacking' with LTSpice.

Jon

On Dec 18, 3:33=A0am, Jon Kirwan wrote:

Try this - with whatever NPN and PNP transistors suit you.

Version 4 SHEET 1 880 724 WIRE -816 -512 -912 -512 WIRE -80 -512 -816 -512 WIRE 288 -512 -80 -512 WIRE 416 -512 288 -512 WIRE 480 -512 416 -512 WIRE 288 -448 288 -512 WIRE -80 -384 -80 -512 WIRE 416 -320 416 -512 WIRE 288 -272 288 -368 WIRE 352 -272 288 -272 WIRE 288 -144 288 -272 WIRE -80 -96 -80 -304 WIRE 64 -96 -80 -96 WIRE 224 -96 64 -96 WIRE -80 -32 -80 -96 WIRE 288 -32 288 -48 WIRE 416 -32 416 -224 WIRE 416 -32 288 -32 WIRE -816 0 -816 -512 WIRE 416 0 416 -32 WIRE 64 64 64 -96 WIRE 416 96 416 80 WIRE 640 96 416 96 WIRE -80 112 -80 48 WIRE 0 112 -80 112 WIRE 416 112 416 96 WIRE -80 160 -80 112 WIRE 416 224 416 192 WIRE 416 224 272 224 WIRE 272 256 272 224 WIRE -80 304 -80 240 WIRE 64 304 64 160 WIRE 64 304 -80 304 WIRE 208 304 64 304 WIRE 416 400 416 224 WIRE -80 448 -80 304 WIRE 272 448 272 352 WIRE 352 448 272 448 WIRE 272 512 272 448 WIRE -816 672 -816 80 WIRE -816 672 -864 672 WIRE -80 672 -80 528 WIRE -80 672 -816 672 WIRE 64 672 -80 672 WIRE 272 672 272 592 WIRE 272 672 64 672 WIRE 416 672 416 496 WIRE 416 672 272 672 WIRE 480 672 416 672 WIRE 64 704 64 672 FLAG 64 704 0 SYMBOL npn 224 -144 R0 SYMATTR InstName Q1 SYMBOL npn 352 400 R0 SYMATTR InstName Q5 SYMBOL npn 0 64 R0 SYMATTR InstName Q3 SYMBOL pnp 352 -224 M180 SYMATTR InstName Q4 SYMBOL pnp 208 352 M180 SYMATTR InstName Q2 SYMBOL res 400 -16 R0 SYMATTR InstName R1 SYMATTR Value 10R SYMBOL res 400 96 R0 SYMATTR InstName R2 SYMATTR Value 10R SYMBOL res 272 -464 R0 SYMATTR InstName R3 SYMATTR Value 680R SYMBOL res 256 496 R0 SYMATTR InstName R4 SYMATTR Value 680R SYMBOL Misc\\xvaristor -96 -48 R0 SYMATTR InstName U1 SYMATTR Value 1k SYMBOL current -80 -384 R0 SYMATTR InstName I1 SYMBOL res -96 144 R0 SYMATTR InstName R5 SYMATTR Value 680R SYMBOL current -80 448 R0 SYMATTR InstName I2 SYMBOL voltage -816 -16 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value "" TEXT -520 552 Left 0 ;Constant current load, nominally 1mA TEXT -536 -344 Left 0 ;Current drive, quiescent value 1mA

The pot at U1 lets you set up the standing current current through the output stage; the "synthetic diode" formed by U1, R5 and Q3 is trimmed to match the Vbe dropped across Q1 and Q2 plus about 200mV to give you a standing current of about 10mA through Q4 and Q5.

It is a good idea to thermally bond Q1, Q2 and Q3 - they never get that hot, but if Q1 and Q2 do get warm, this then lowers the Vbe of Q3 and reduces the standing current.

The version of this I built more thirty years ago now worked well for many years - I'd grafted it on to TI discrete audio amplifier design that didn't protect the base-emitter junctions in the pre-amplifier against reverse bias and I eventually got sick of finding, replacing and protecting the succession of degraded transistors that stopped the pre-amplifier from working right over the years, but it's still down in the basement waiting for a burst of enthusiasm.

-- Bill Sloman, Nijmegen

Thanks. I see this web page where Figure 2 reminds me of your circuit

-- obviously filled out with part values, though.

I had been thinking more like the Figure 1 case, though. In earlier days NPNs were better and designs emphasized them. In my own junk box, I've a lot more NPN BJTs that PNP and for that reason I prefer an emphasis on NPN over PNP.

Neither of those schematics on the above web page use a long tailed pair diff amp, which I'd also like to play with more in the voltage gain part of the amplifier design. And I need to condition the output of a phono-jack as the very first stage. For that, I need to learn more about the output drivers used for them and what things to worry about.

Jon

Finnegan's Finagling Factor: that number which, added to, subtracted from, multiplied by, or divided into the number you actually got, gives you the result you really wanted.

In

Consilience is using one /technique/ as a reference to improve another, grinding one straight edge against another to make both truer.

Adjusting your data to match your theory? Adjusting multiple data sets so they agree, corrupting all so that none is true? That's the opposite. Kind of a liar's version of cross-checking, a perversion of proof by multiple independent proofs.

That's just plain cheating.

-- Cheers, James Arthur

Figure 2 and Figure 3 both show a proper synthetic diode - I couldn't find a potentiometer symbol in LTSpice, and the version I drew probably wouldn't work. That it wouldn't work should have been obvious to me at the time, but my subconscious error-checker doesn't work all that fast.

The trick with the synthetic diode is to get just enough voltage drop over the base-emitter junction of the relevant transistor (Q3 in my circuit) to divert most of the quiescent drive current through the transistor leaving enough to develop the roughly 1.6V desired across the pot. With a nominal 1mA drive I should have aimed for around 0.5mA through the transistor and 0.5mA through the pot - but that would have meant a 3k3 pot, which you can't buy. A 5k pot, which you can buy - and I'd go for a 22-turn 19mm pot, because they can be set very precisely, and stay set - would then take 0.32mA, leaving 0.68mA running through the transistor. It is a good idea to pad the bottom of the pot with a fixed resistor to stop youself setting up a very large quiescent current through the output stage - 2k2 strikes me as about right here in series with a 5k pot, but you'd want to tolerance it against the worst case Vbe (lowest) for the transistor you selected and the worst case pot resistance (4k5 for the parts I'd use)

Douglas Self always seems to use a long-tailed pair input stage, as here

If you run down the page far enough you get to his version of the synthetic diode.

It is years since I read any of his stuff in detail, but from what I remember it is all remarkably sensible and backed up with even more sensible testing and measurement.

-- Bill Sloman, Nijmegen

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No it doesn't. If from a volcano, the dust in the air lowers temperatures. Ditto for combustion particulates ('global dimming'), a- bomb debris, agriculture dust, offset by albedo effects, offset by....the unknowable.

-- Cheers, James Arthur

This is a serious misreading of what I was saying, as would be obvious to anybody who had gone on to read the substance of what I wrote. The Wikipedea discussion of the University of Alabama at Hintsville's (UAH) correction from 5.1 to 5.2 points out that

/quote

For some time, the UAH satellite data's chief significance was that they appeared to contradict a wide range of surface temperature data measurements and analyses showing warming in line with that estimated by climate models. In April 2002, for example, an analysis of the satellite temperature data showed warming of only 0.04 =B0C per decade, compared with surface measurements showing 0.17 =B1 0.06 =B0C per decade. The correction of errors in the analysis of the satellite data, as noted above, have brought the two data sets more closely in line with each other.

Christy et al. (2007) find that the tropical temperature trends from radiosondes matches closest with his v5.2 UAH dataset.[17] Furthermore, they assert there is a growing discrepancy between RSS and sonde trends beginning in 1992, when the NOAA-12 satellite was launched[18]. This research found that the tropics were warming, from the balloon data, +0.09 (corrected to UAH) or +0.12 (corrected to RSS) or 0.05 K (from UAH MSU; =B10.07 K room for error) a decade.

/end quote

Since the corrections were based on a more thorough analysis of the way orbital decay affects the satellite observations, this isn't Finagle factoring, but a way of making better sense of the data. That the improved processing brings the results better into line with independent observations of the same regions is a bonus and provides some confidence that the investigators have finally concentrated their attention on aspects of the data processing that needed it.

Which is exactly what happend here

The UAH were adjusting their data processing, not their raw data, to correct for problems that other investigators had demonstrated to be signficant.

The only theory invlovlved here is the oen that say the same lump of gas should have the same temperature at the same time if you measure it with several different instruments by several different techniques.

If that had been what was going on, it would have been reprehensible. The fact that you feel free to make such a claim, without having gone to trouble of working out what was actually being discussed, is no less reprehensible.

A totally perverse misinterpretation, most likely based on ignorant and careless preconceptions.

Which is a fair description of your post. You claim to understand the kind of climate models involved, and to have some kind of privileged access to the gossip that goes around between the modellers, but now have the gall to post this slanderous misunderstanding of what was going on.

-- Bill Sloman, Nijmegen

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hat

That is the basic point about University of Alabama at Huntsville's (UAH) correcting their data processing from 5.1 to 5.2. As the Wikipedia write-up makes clear, they were driven to it when other investigators showed that there was a problem with other satellite data that could be corrected in a way that wasn't being done with in UAH 5.1 data processing.

The UAH corrections look more like 1945 than 1922.

-- Bill Sloman, Nijmegen

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That in the Wikipedia article, if you can be bothered to read it carefully.

The UAH data got corrected in rather less than 40 years. People may be getting better, or - more likely - the temperature distribuiton up through the atmosphere is of more immediate interest that seven and eighth significant digits of the speed of light.

-- Bil Sloman, Nijmegen

Or perhaps the increased velocity of communications and pressure to publish has changed the time response. The real issue is whether experimental results are influenced by the numbers from other experimenters, or by desired results, namely by psychological pressures. In the AGW case, it sure looks like it is, because the choice of "corrections" is arbitrary. "Manufacturing consensus."

The thing about the light speed measurements is that they started in the 1% or so error range and converged down to the ppb range, and no researcher could ever question previous measurements to more than a few parts per thousand, later parts per million. Even air temperature measurements are still all over the place, and climate theory needs not just temperatures now, but accurate temperature histories over hundreds or thousands of years. The situations are very different.

John